Monday, September 28, 2015

New paper: Getting a cue before getting a clue

It seems the last few months on this blog have been all about inference generation... I'm happy to say this post is also the case! I'm excited to announce that I have a new paper out in the journal Neuropsychologia entitled "Getting a cue before getting a clue: Event-related potentials to inference in visual narrative comprehension."

This paper examines the brain response to the generation of inference in a particular narrative construction in comics. As far as I know, it's the first neuroscience paper to examine inference specifically in visual narratives. Specifically, our analysis focused on comparing sequences like these:

The top sequence (a) is from an actual Peanuts strip. What is key here is that you never see the main event of the sequence: Linus retrieving the ball. In my narrative structure, this "climactic" state would be called a "Peak." Rather, the image of Charlie watching ambiguously hides this event, but that panel is more characteristic of a "Prolongation" that extends the narrative further without much action.

Contrast this with (b), which has a structure that also appears in several Peanuts strips. Here, the third panel also does not show the main event (the same event as "a") but here the exclamation mark implies at least that some event is happening at least. In my narrative structure, this cue is enough to tell you that this panel is the climax, despite not showing you what the climax is.

We were curious then if the brain distinguishes between these types of sequences which both should require inference (indeed, the same inference) but differ in their narrative structure (spoiler: it does!). You can read a full pdf of the paper here. Here's the full abstract and reference:

Abstract:

Inference has long been emphasized in the comprehension of verbal and visual narratives. Here, we measured event-related brain potentials to visual sequences designed to elicit inferential processing. In Impoverished sequences, an expressionless “onlooker” watches an undepicted event (e.g., person throws a ball for a dog, then watches the dog chase it) just prior to a surprising finale (e.g., someone else returns the ball), which should lead to an inference (i.e., the different person retrieved the ball). Implied sequences alter this narrative structure by adding visual cues to the critical panel such as a surprised facial expression to the onlooker implying they saw an unexpected, albeit undepicted, event. In contrast, Expected sequences show a predictable, but then confounded, event (i.e., dog retrieves ball, then different person returns it), and Explicit sequences depict the unexpected event (i.e., different person retrieves then returns ball). At the critical penultimate panel, sequences representing depicted events (Explicit, Expected) elicited a larger posterior positivity (P600) than the relatively passive events of an onlooker (Impoverished, Implied), though Implied sequences were slightly more positive than Impoverished sequences. At the subsequent and final panel, a posterior positivity (P600) was greater to images in Impoverished sequences than those in Explicit and Implied sequences, which did not differ. In addition, both sequence types requiring inference (Implied, Impoverished) elicited a larger frontal negativity than those explicitly depicting events (Expected, Explicit). These results show that neural processing differs for visual narratives omitting events versus those depicting events, and that the presence of subtle visual cues can modulate such effects presumably by altering narrative structure.